Add logging system to pub and sprinkle some logging in.

utils/pub/entrypoint.dart

Index: utils/pub/entrypoint.dart
diff --git a/utils/pub/entrypoint.dart b/utils/pub/entrypoint.dart
index 521f2614c4bdae4b88cf55fbc88be08a0a56c703..b5cc6f31159664b3e8f18250345dbd0b246d503f 100644
--- a/utils/pub/entrypoint.dart
+++ b/utils/pub/entrypoint.dart
@@ -6,6 +6,7 @@ library entrypoint;
 
 import 'io.dart';
 import 'lock_file.dart';
+import 'log.dart' as log;
 import 'package.dart';
 import 'root_source.dart';
 import 'system_cache.dart';
@@ -81,6 +82,7 @@ class Entrypoint {
       if (!exists) return new Future.immediate(null);
       // TODO(nweiz): figure out when to actually delete the directory, and when
       // we can just re-use the existing symlink.
+      log.fine("Deleting package directory $packageDir.");

[nweiz, 2012/12/05 23:56:54]

Redundant with deleteDir.

[Bob Nystrom, 2012/12/06 01:33:26]

Replaced path with package name in log. I still want to log here so I know why
the directory is being deleted.

       return deleteDir(packageDir);
     }).chain((_) {
       if (id.source.shouldCache) {
@@ -161,6 +163,8 @@ class Entrypoint {
   Future<LockFile> _loadLockFile() {
     var completer = new Completer<LockFile>();
     var lockFilePath = join(root.dir, 'pubspec.lock');
+
+    log.fine("Loading lockfile $lockFilePath.");

[nweiz, 2012/12/05 23:56:54]

"$lockFilePath" is redundant.

[Bob Nystrom, 2012/12/06 01:33:26]

Done.

     var future = readTextFile(lockFilePath);
 
     future.handleException((_) {
@@ -168,8 +172,9 @@ class Entrypoint {
       // probably wrong and we should notify the user.
       fileExists(lockFilePath).transform((exists) {
         if (!exists) return;
-        printError("Error reading pubspec.lock: ${future.exception}");
+        log.error("Error reading pubspec.lock: ${future.exception}");
       }).then((_) {
+        log.fine("No lock file at $lockFilePath, creating empty one.");
         completer.complete(new LockFile.empty());
       });
 
@@ -190,7 +195,9 @@ class Entrypoint {
       if (id.source is! RootSource) lockFile.packages[id.name] = id;
     }
 
-    return writeTextFile(join(root.dir, 'pubspec.lock'), lockFile.serialize());
+    var lockFilePath = join(root.dir, 'pubspec.lock');
+    log.fine("Saving lockfile $lockFilePath.");

[nweiz, 2012/12/05 23:56:54]

"$lockFilePath" is redundant.

+    return writeTextFile(lockFilePath, lockFile.serialize());
   }
 
   /**